/*
silverPDF is sponsored by Aleyant Systems (http://www.aleyant.com)

silverPDF is based on PdfSharp (http://www.pdfsharp.net) and iTextSharp (http://itextsharp.sourceforge.net)

Developers: Ai_boy (aka Oleksii Okhrymenko)

Permission is hereby granted, free of charge, to any person
obtaining a copy of this software and associated documentation
files (the "Software"), to deal in the Software without
restriction, including without limitation the rights to use,
copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the
Software is furnished to do so, subject to the following
conditions:

The above information and this permission notice shall be
included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR SPONSORS
BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.

*/
#region PDFsharp - A .NET library for processing PDF
//
// Authors:
//   Stefan Lange (mailto:Stefan.Lange@pdfsharp.com)
//
// Copyright (c) 2005-2008 empira Software GmbH, Cologne (Germany)
//
// http://www.pdfsharp.com
// http://sourceforge.net/projects/pdfsharp
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the "Software"),
// to deal in the Software without restriction, including without limitation
// the rights to use, copy, modify, merge, publish, distribute, sublicense,
// and/or sell copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 
// DEALINGS IN THE SOFTWARE.
#endregion

using System;
#if GDI
using System.Drawing;
using System.Drawing.Drawing2D;
#endif
#if WPF
using System.Windows.Media;
#endif

namespace PdfSharp.Drawing
{
  // In GDI+ the functions Save/Restore, BeginContainer/EndContainer, Transform, SetClip and ResetClip
  // can be combined in any order. E.g. you can set a clip region, save the graphics state, empty the
  // clip region and draw without clipping. Then you can restore to the previous clip region. With PDF
  // this behaviour is hard to implement. To solve this problem I first an automaton that keeps track
  // of all clipping paths and the current transformation when the clip path was set. The automation
  // manages a PDF graphics state stack to calculate the desired bahaviour. It also takes into consideration
  // not to multiply with inverse matrixes when the user sets a new transformation matrix.
  // After the design works on pager I decided not to implement it because it is much to large-scale.
  // Instead I lay down some rules how to use the XGraphics class.
  //
  // * Before you set a transformation matrix save the graphics state (Save) or begin a new container
  //   (BeginContainer).
  // 
  // * Instead of resetting the transformation matrix, call Restore or EndContainer. If you reset the
  //   transformation, in PDF must be multiplied with the inverse matrix. That leads to round off errors
  //   because in PDF file only 3 digits are used and Acrobat internally uses fixed point numbers (until
  //   versioin 6 or 7 I think).
  //
  // * When no clip path is defined, you can set or intersect a new path.
  //
  // * When a clip path is already defined, you can always intersect with a new one (wich leads in general
  //   to a smaller clip region).
  //
  // * When a clip path is already defined, you can only reset it to the empty region (ResetClip) when
  //   the graphics state stack is at the same position as it had when the clip path was defined. Otherwise
  //   an error occurs.
  //
  // Keeping these rules leads to easy to read code and best results in PDF output.

  /// <summary>
  /// Represents the internal state of an XGraphics object.
  /// </summary>
  internal class InternalGraphicsState
  {
    public InternalGraphicsState(XGraphics gfx)
    {
      this.gfx = gfx;
    }

    public InternalGraphicsState(XGraphics gfx, XGraphicsState state)
    {
      this.gfx = gfx;
      this.state = state;
      state.InternalState = this;
      //#if GDI
      //      //GdiGraphicsState = state.GdiState;
      //      this.gfx = gfx;
      //      this.state = state;
      //      state.InternalState = this;
      //#endif
      //#if WPF
      //      this.gfx = gfx;
      //      this.state = state;
      //      state.InternalState = this;
      //#endif
    }

    public InternalGraphicsState(XGraphics gfx, XGraphicsContainer container)
    {
      this.gfx = gfx;
      container.InternalState = this;
      //#if GDI
      //      //GdiGraphicsState = container.GdiState;
      //      this.gfx = gfx;
      //      container.InternalState = this;
      //#endif
      //#if WPF
      //      this.gfx = gfx;
      //      container.InternalState = this;
      //#endif
    }

    /// <summary>
    /// Gets or sets the current transformation matrix.
    /// </summary>
    public XMatrix Transform
    {
      get { return this.transform; }
      set { this.transform = value; }
    }
    XMatrix transform = XMatrix.Identity;

    public void Pushed()
    {
#if GDI
#endif
#if WPF
#endif
    }

    public void Popped()
    {
      this.invalid = true;
#if GDI
#endif
#if WPF
      if (this.gfx.targetContext == XGraphicTargetContext.WPF)
      {
        for (int idx = 0; idx < this.transformPushLevel; idx++)
          this.gfx.dc.Pop();
        this.transformPushLevel = 0;
        for (int idx = 0; idx < this.geometryPushLevel; idx++)
          this.gfx.dc.Pop();
        this.geometryPushLevel = 0;
      }
#endif
    }

    internal bool invalid;

#if GDI_
    /// <summary>
    /// The GDI+ GraphicsState if contructed from XGraphicsState.
    /// </summary>
    public GraphicsState GdiGraphicsState;
#endif

#if WPF
    public void SetTransform(MatrixTransform transform)
    {
      this.gfx.dc.PushTransform(transform);
      this.transformPushLevel++;
    }
    int transformPushLevel;

    public void SetClip(Geometry geometry)
    {
      this.gfx.dc.PushClip(geometry);
      this.geometryPushLevel++;
    }
    int geometryPushLevel;

#endif

    internal XGraphics gfx;
    internal XGraphicsState state;
    // /// <summary>
    // /// The GDI+ GraphicsContainer if contructed from XGraphicsContainer.
    // /// </summary>
    // public GraphicsContainer GdiGraphicsContainer;

  }
}
